Device for taking samples of liquid specimens especially for the automatic analysis apparatus

ABSTRACT

A device for taking samples of liquid specimens, such as blood, microbiological suspension and the like for use with an automatic analysis apparatus. The device comprises a sampling head including a hollow needle connected to a pump at one end. The needle is fixed to a support mounted for movement with an endless belt with horizontal and vertical sides in two perpendicular directions. Means are provided for washing the exterior of the needle and are mounted for movement with the needle in one of the perpendicular directions; they comprise a block with bores, one of the bores being connected to a tube carrying a washing liquid thereto and another of the bores being connected to a tube carrying the washing liquid away therefrom. Optical or electrical means may be provided for positioning the needle relative to a test tube containing the liquid to be analysed.

Rousselet et al.

[ DEVICE FOR TAKING SAMPLES OF LIQUID SPECIMENS ESPECIALLY FOR THEAUTOMATIC ANALYSIS APPARATUS [75] Inventors: Andre Rousselet, Eaubonne;

Pierre Durand, Fresnes, both of France [73] Assignee: Hoffmann-La RocheInc., Nutley,

[22] Filed: Dec. 29, 1971 [21] Appl. No.: 213,526

[30] Foreign Application Priority Data Dec. 29, 1970 France ..7047006521 U.S. Cl 73/423 A [51] Int. Cl G011 1/16 [58] Field of Search 73/423A [56] References Cited UNITED STATES PATENTS 3,552,212 1/1971 Ohlinml73/423 A 3,327,535 6/1967 Sequiera..... 73/423 A Isreeli 73/423 A,flrjmqry EaemLner-S; Qt qmsntwsn shex Attorney-SamuelL Welt, JacobFrank et al.

[57] ABSTRACT A device for taking samples of liquid specimens, such asblood, microbiological suspension and the like for use with an automaticanalysis apparatus. The device comprises a sampling head including ahollow needle connected to a pump at one end. The needle is fixed to asupport mounted for movement with an endless belt with horizontal andvertical sides in two perpendicular directions. Means are provided forwashing the exterior of the needle and are mounted for movement with theneedle in one of the perpendicular directions; they comprise a blockwith bores, one of the bores being connected to a tube carrying awashing liquid thereto and another of the bores being connected to atube carrying the washing liquid away therefrom. Optical or electricalmeans may be provided for positioning the needle relative to a test tubecontaining the liquid to be analysed.

6 Claims, 8 Drawing Figures minimum m5 3748311 SHEEI 1 0F 3 FIG. 3 20 IFIG. 6'

PATENT JUL 3.1 I975 SHEET 2 OF 3 A FIG. 2

PATENIEDJUL31 I915 3'. 748.91 1

SHEET 3 (IF 3 DEVICE FOR TAKING SAMPLES OF LIQUID SPECIMENS ESPECIALLYFOR THE AUTOMATIC ANALYSIS APPARATUS The invention relates to a samplingdevice for liquid specimens, particularly for automatic analysisapparatus having a hollow needle for taking a sample connected at an endto a pump.

Automatic analysis apparatus, in particular for the biochemical analysisof blood, are known which comprise a first plurality of test tubes on asupport containing liquid specimens to be analysed, and in whichfractions of the liquid specimens must be taken by a sampling device tobe transferred into a second plurality of test tubes, for example fordiluting or adding fractions of appropriate reagents thereto.

Such a sampling device must satisfy a number of conditions, inparticular allow the successive taking of fractions of different typesof specimens which requires interior and exterior washing of thesampling head, generally a hollow needle connected at an end to a pump,for example of the peristaltic type.

An object of the present invention is to provide a sampling device whoseoperation is sure and simple which satisfies the required condition, inparticular with respect to washing the sampling head inside and outside.

Another object of the present invention is to provide such a devicewhich operates automatically to take samples of the specimens to beanalysed.

According to the invention the needle is fixed to a movable support,means for washing the outside of the needle moving at least in part withsaid needle.

Preferably, and according to a further feature of the device, themovable support is adapted to be driven in two perpendicular directions,the washing means being movable with the needle in one of these twodirections.

The invention will be fully understood by the desceiption which followsmade by way for example and with reference to the accompanying drawings,in which FIG. 1 is a diagrammatic showing of an automatic analysisapparatus comprising the device according to the invention FIG. 2 is aview partly in elevation and partly in section of an embodiment of thedevice according to the invention FIG. 3 is a sectional view on a largerscale of a device for washing the outside of the sampling head for thedevice according to the invention FIG. 4 is a view partly in elevationand partly in section of another embodiment of the device FIG. 5 is across section taken along the line V-V in FIG. 4

FIG. 6 is a schematic view of a sampling head for still anotherembodiment FIG. 7 is a schematic view of a sampling head for a furtherembodiment and FIG. 8 is a view similar to that of FIG. 7 but for amodification.

Reference is first made to FIG. 1 which shows diagrammatically ananalysis apparatus comprising a table 11 driven for rotation in thedirection of the arrow f and which has at its periphery a firstplurality of containers 12,, 12 etc., such as test tubes removablysecured thereto. The containers 12 contain liquid specimens to beanalysed which must be partially decanted or transferred into a secondplurality of containers 13 on a second table 14 where they are, forexample, diluted or mixed with appropriate reagents for their analysis.The liquid in the containers 12 may be blood, one of its constituentssuch as plasma, or another organic liquid. It may also be, for example,a microbiological suspension.

During the rotation of the table 11 which is preferably step-by-step thecontainers 12 pass in succession in front of a sampling device 10 bymeans of which fractions of the contents of containers 12,, 12 etc., arebrought to the containers 13 13 etc., respectively. The device 10 (FIG.2) comprises a hollow needle 20 or sampling head one end 21 of which isconnected by a tube (not illustrated) to a pump, for example aperistaltic pump. The sampling head 20 is carried by a bracket 22secured to a pivot 23 on a link 24 of an endless chain belt 25 withvertical sides 27a, 27b and horizontal sides 29a, 29b driven by a gearwheel 26 connected to a suitable transmission comprising a pinion gear28 with a motor (not shown).

The bracket 22 is secured to a plate 30 slidably mounted on two tracks31, 32 on a frame 33 which in turn is slidably mounted in a directionperpendicular to the tracks 31, 32 on guiding rods 34, and 35 fixed onthe housing 36 of the device.

A second bracket 37, carrying at its free end a device 38 for washingthe outside of the needle, is mounted on a frame 33. The device 38,(FIG. 3), comprises a block 39 with a bored cylindrical passage '40having a diameter slightly greater than the outer diameter of the needle20 which is extended downwardly by a truncated conical orifice 41 andupwardly by a truncated conical orifice 42 with a cylindrical bore 43 atits top. A small diameter pipe 44 carrying liquid for washing isdischarged in the bore 43, and a pipe 45 having a diameter larger thanthat of the pipe 44 and connected to a suction source is incommunication with the orifice 41.

The operation of the device is as follows Starting from the solid-lineposition shown in FIG-'2 in which the sampling head extends into a tube12 mounted on a test tube holder PT for taking a fractional sample ofthe contents of the test tube, the belt 25 is set into motion, the plate30 integral with the pivot 23 undergoes translatory movement in thedirection of the arrow P guided by the tracks 31 and 32 carrying thebracket 22 and the sampling head 20 which passes through the washingdevice 38, which is then not in motion nor is the frame 33 to which itis fixed by'the bracket 37.

During this phase of the operation, the liquid taken from the test tube12 is carried to a container 13. In addition, the introduction of awashing liquid through the small diameter pipe 44 into the device 38 andthedischarge through from the device 38 by the pipe 45 of largerdiameter causes, owing to the shape of the bores 41, 42, 43, a vortexmovement of the liquid which ensures satisfactory washing of the outsideof the needle 20.

. When the link 24 moves-along the upper horizontal side 29a of theendless belt 25, the pivot is displaced in the direction of the arrow q,perpendicular to the arrow p, slidingly displacing the frame 33-alongthe rods'3'4 and 35. This movement-of the frame 33 which is aiso commonto the bracket 37 and the'washing device 38 continues untill thesampling head 20 reaches the position shown in dash-dotted lines in FIG.2 in which' the sampling head is in line with the container 9 containinga liquid for washing the interior of the sampling head. The plate 30 isthen displaced in the direction opposite that of the arrow p until thesampling head 20 is at least partially immersed in the washing liquid inthe container 9. The peristaltic pump pumps through the sampling head 20the amount of liquid contained in the container 9, the discharge of thisliquid ensuring the washing of the interior of the sampling head.

A micro-switch 40 controls the movement of the belt in the oppositedirection causing the upward movement of the sampling head 20 with afurther pass through the exterior washing device the movement of thebelt 25 continuing, the frame 33 is displaced in the direction oppositeto that of the arrow q, then it stops by the actuation of a micro-switch41 when the needle 20 is once again in line above the test tube 12. Aprogramming device (not illustrated) then brings another test tube 12containing another specimen to be sampled in position under the samplinghead 20, and controls the movement of the belt 25 causing the loweringof the sampling head into the liquid to be sampled from the test tubejust brought into line with the sampling head. During the descendingmovement of the sampling head 20, the latter may puncture a stopper Bcovering the open end of the test tube 12.

When the plate has returned to the solid-line position shown in FIG. 2,the actuation of the microswitch 42 causes the belt 25 to stop theprogramming device controls the taking of the liquid to be analysed fromthe next test tube 12, once this operation has been effectuated, thebelt 25 starts moving again in the direction of the arrow p in order toeffect once again the above described cycle.

The present device may also be used for effecting the dilution of thesamples of the specimens taken from the test tubes-l2 automatically. inthis case, the container 9 of liquid for washing the interior of theneedle is eliminated means are provided for the sampling head 20 toreceive a diluting liquid which washes the interior of the sampling headthe means for washing the exterior of-the needle being as describedabove. The container into which the portion of the liquid from the tube12 is decanted may, in this case, be fixed to the tube carrier PT.

In the embodiment shown in FIGS. 4 and 5, an auxiliary positioningdevice 50 comprising two arms 51 and 52 parallel to the sides of thesampling head adapted to straddle the test tube 12 is associated withthe sampling head. The arm 51 carries a photo cell 53 opposite a lightsource 54 carried by the arm 52.

Such a device for use in particular with sampling devices for bloodanalysis appratus enables a precis positioning of the sampling head 20in the test tube 12 containing at its lower end the medium to beanalysed, generally an opaque globular mass G, topped with blood plasmaPS which is transparent to the light emitted by the source 54.

In a modification, (FIG. 6), the metal needle 20 is surrounded along apart of its length by an electrically insulating sleeve 70, an outerconductive tube 71 is fitted on the sleeve. The needle 20 and the tube71 are electrically connected by conductors 72 and 73 to an A.C. voltagesource 74, the frequency of which is adjusted as a function of theliquid into which the needle is to be immersed, and a device formeasuring the resistance by resistivity of the medium into which theneedle is to immersed. A precision positioning of the sampling needle 20in the test tube 12 contained the' liquid medium to be analysed is thusobtained as in the embodiment of FIGS. 4 and 5.

Reference is now made to FIG. 7 relative to another improvement of thepresent device. In this embodiment a syringe device 60 is associatedwith the hollow sampling needle the syringe device comprises a piston 61slidably mounted in a cylinder 62 in communication with a tube 63 forintroducing air for-drying and with a tube 64 connected to the needle.The piston 61 has a chamfered edge 68 at its front face for forming inthe vicinity of the tubes 63 and 64 a space 65 closed in the directionof the tube 63 by a non-return valve 66 which is substituted by aresilient blade 67 in the modified embodiment of FIG. 8.

After the discharge of the liquid taken by means of the needle, thestream of air under pressure in the tube 63 blows out the amount ofliquid remaining in the needle and dries the same thereby ensuring aparticularly effective rinsing of the interior of the sampling device.

What is claimed is:

l. A device for taking samples of liquid specimens for use in anautomatic analysis apparatus, comprising: a hollow sampling needleadapted to be connected at one end to a pump; a movable support of saidneedle from a first to second position for respective insertion in afirst and second containers; and, means for washing the exterior of saidneedle operatively connected for movement with said needle from saidfirst to second position.

2. A device for taking samples of liquid specimens for use in anautomatic analysis apparatus comprising: a hollow sampling needleadapted to be connected at one end to a pump; a movable support of saidneedle displaceable for translatory movement in two perpendiculardirections; and means for washing the exterior of said needleoperatively connected for movement with said needle in one of saiddirections.

3. A device for taking samples of liquid specimens for use in anautomatic analysis apparatus, comprising: a hollow sampling needleadapted to be connected at one end to a pump; movable support means forsaid needle mounted for movement with an endless belt having horizontaland vertical sides and further including vertical tracks for guiding thetranslatory movement of the support in one direction, whereby saidvertical tracks are fixed to a frame mounted for sliding movement onhorizontal tracks fixed to a housing of the device; and, means forwashing the exterior of said needle operatively connected for movementat least in part with said needle.

4. A device according to claim 3, wherein the means for washing theexterior of the needle is mountedon an end of a bracket fixed to theframe.

5. A device for taking samples of liquid specimens for use in anautomatic analysis apparatus, comprising: a hollow sampling needleadapted to be connected at one end to a pump; container means for theliquid specimen to be sampled; a movable support of said needle; meansfor washing the exterior of said needle operatively connected formovement at least in part with said needle; and, means for automaticallypositioning the sampling needle in said container means, including alight source and a transducer sensitive to the light from said source,said light source being mounted on one armand said transducer beingmounted on another arm of a pair of arms extending parallel to saidneedle.

cally positioning the sample needle in said container including a metaltube extending around the needle and electrically insulated therefrom,the metal tube and the needle being connected to an AC source as well asto means for measuring the resistance of the liquid specimens to beanalyzed.

1. A device for taking samples of liquid specimens for use in anautomatic analysis apparatus, comprising: a hollow sampling needleadapted to be connected at one end to a pump; a movable support of saidneedle from a first to second position for respective insertion in afirst and second containers; and, means for washing the exterior of saidneedle operatively connected for movement with said needle from saidfirst to second position.
 2. A device for taking samples of liquidspecimens for use in an automatic analysis apparatus comprising: ahollow sampling needle adapted to be connected at one end to a pump; amovable support of said needle displaceable for translatory movement intwo perpendicular directions; and means for washing the exterior of saidneedle operatively connected for movement with said needle in one ofsaid directions.
 3. A device for taking samples of liquid specimens foruse in an automatic analysis apparatus, comprising: a hollow samplingneedle adapted to be connected at one end to a pump; movable supportmeans for said needle mounted for movement with an endless belt havinghorizontal and vertical sides and further including vertical tracks forguiding the translatory movement of the support in one direction,whereby said vertical tracks are fixed to a frame mounted for slidingmovement on horizontal tracks fixed to a housing of the device; and,means for washing the exterior of said needle operatively connected formovement at least in part with said needle.
 4. A device according toclaim 3, wherein the means for washing the exterior of the needle ismounted on an end of a bracket fixed to the frame.
 5. A device fortaking samples of liquid specimens for use in an automatic analysisapparatus, comprising: a hollow sampling needle adapted to be connectedat one end to a pump; container means for the liquid specimen to besampled; a movable support of said needle; means for washing theexterior of said needle operatively connected for movement at least inpart with said needle; and, means for automatically positioning thesampling needle in said container means, including a light source and atransducer sensitive to the light from said source, said light sourcebeing mounted on one arm and said transducer being mounted on anotherarm of a pair of arms extending parallel to said needle.
 6. A device fortaking samples of liquid specimens for use in an automatic analysisapparatus, comprising: a hollow sampling electrically conductive needleadapted to be connected at one end of a pump; a container provided forthe liquid specimen to be sampled; a movable support of said needle;means for washing the exterior of said needle operatively connected formovement at least in part with said needle; and, means for automaticallypositioning the sample needle in said container including a metal tubeextending around the needle and electrically insulated therefrom, themetal tube and the needle being connected to an AC source as well as tomeans for measuring the resistance of the liquid specimens to beanalyzed.